Electric switch



April 3, 1945- P. M. cHRlsTENsx-:N 2,372,881

ELECTRIC SWITCH 2 Sheets-Sheet l Filed July 6' 1942 April 3, 1945. P. M cHRlsTr-:NSEN 2,372,881

ELECTRIC SWITCH Filed Julyv 6, 1942 2 Sheets-Sheet 2 "MIU Patented Apr. 3, 1945 UNITED STATES PATENT GFFICE ELECTRIC SWITCH Application July .6, 1942, Serial No. 449,851

11 Claims.

with one or more bridging contacts respectively adapted to electrically connect opposite pairs of stationary switch contacts. The switch t which the present invention is applicable is of the type `disclosed in U. S. Patents 1,754,443 and 1,754,445 issued to Sachs in 1930 and also U. Si. Patent 2,005,686 issued t0 Sachs in 1935. It will be 11nderstood, however, that while the invention is applicable to switches of the type referred to, it is not necessarily so limited as concerns its broader aspects.

It is the principle of the present invention to provide an electric switch in which the conta-cting areas of the stationary contacts and the movable bridging contact for connecting the same are materially increased over similar switches of standard construction such as shown in said patents and self-alignment of the respective areas is permitted.

These objects of the invention are attained by providing a movable contact which, in the preferred embodiment of the invention, comprisesv a pair of nested U-shaped members having substantially flat sides which serve as contact surfaces adapted to engage spaced stationary contacts on both sides of each stationary contact as distinguished from contact with one surface only of each oi the stationary contacts. The U- shaped 'members are somewhat loosely mounted on the slide carrying the same to afford limited and independent floating movement of the members which permits the sides of said members to become self-aligned with the surfaces of the stationary contacts engaged thereby.

Other objects and details of the inventionrwill be apparent from the following specification and the attached drawings.

The accompanying drawings show the embodiment of the invention which is deemed preferable, but it will be understood that the drawings are intended for illustrative purposes only and are not to be construed as denning or limiting the scope of the invention, the claims forming a part of this specication being relied upon for that purpose.

In the drawings, Fig. 1 is a plan View of a switch embodying the principles of the invention and in which each movable slide carries a single bridging contact. In this View the ends of the switch casing are removed.

Fig. 2 is a sectional end elevation on the line rig. 3 is a view similar to Fig. 1 and illustrates a switch in which the slide members each carry two bridging contacts.

Fig. 4 is a side. elevation of one of the slides illustrated in Fig. 3, part of the contacts and securing means therefor being broken away to better illustrate details ofthe invention.

Fig. 5 is an exploded fragmentary perspective view of one of the contacts and several portions of the slide.

Fig. 6 is a sectional plan view of the right hand end of the slide illustrated in Fig. 4.

Referring to the drawings, Fig. 1 illustrates a casing or cabinet I0 in which the switching elements are mounted. Insulating blocks t2 respectively carry a pair 0i stationary contacts I4 and I6 each having contact portions I8 which are substantially parallel to and spaced from each other. The contacts IB are also each provided with fuse clips 20 adapted to engage one end of.

a fuse 22. The other end of the fuse is held by a fuse clip 24 which is secured to a terminal 26. Another terminal 2B is secured to each of the contacts I4 whereby either the service or line conduits may be secured to either the terminal 26 or 28.

A plate-like slide 30 formed from a sheet of uniformly thick insulating material such as bre or the like is provided for each block I2, each of said blocks being formed with a suitable guide groove or channel 32 in the base thereof to form a guideway for the slide 3U whereby said slide is guided for rectilinear movement therein.

The slides 3U are also each provided adjacent one end with a slot 34 which extends transversely to the longitudinal axis of the slide. Said slots receive an actuating mem-ber which may be a bail crank 36 pivotally mounted in opposed Walls of the casing I0.

The insulating blocks I2 are each provided with a cap 38 of insulating material which is secured by means such as screws 40 to the block I2. In Fig. 1, one of the caps has been removed to better illustrate the details of the invention. Each cap is provided with a guide groove 42 in the underside thereoi to limit lateral movement ofthe upper edge of the slide 30 as viewed in Fig. 2.

A movable bridging contact generally designated 44 is Vsecured to each slide 30 adjacent the end tlfereof which is opposite that containing the slot The embodiment of the invention illustrated in Fig. 3 differs from that illustrated in Fig. 1 to the extent that the slide in Fig. 3 carries two movable bridging contacts Whereas the slide illusflat to provide contacting surfaces adapted to engage opposite sides of thestationary switch contact portions I8.

One end of slide 38 is provided with a notch 50 which is disposed substantially medially thereofA The notch is, adapted to receive the bend ory connecting portions of the U-shaped members and the depth of the notch 50 is greater than the thickness of the bend portions of the two y U-shaped members mounted therein. Adjacent the outer ends of the sides of the notch 58 are recesses 52.

A retaining member 54 having a flat rear portion 56, extending laterally beyond the sidev surfaces of the slide when mounted thereon, is provided with spaced parallel ears, 58. The retaining member 54 is mounted in the recesses 52 and the flat rear portion 56 of the retaining member closes the outerend of the notch 50 to maintain the U-shaped members 46 and 48 `within the notch. The ears 58 and theslide 38 are apertured toreceive securing means such as rivets 60 by which the retaining member 54 is held in assembled relationship with the'slide 30.

The inner U-shaped member 48 is provided at its free ends with inturned members 62 and the outer T T-shaped member is provided on its free ends with outward turned members 64,'the members 62 and 64 providing flared-mouths for the adjacentsides of U-shaped members 46 and 48 which flared mouths facilitate the .co-engagement of the movable bridging contacts with the stationary contact portions I8 `as is clearly shown in Figs. 1, 3 and 6.

-fInasmuch as the notch 58 is of greater depth than'the thickness of the two bend portions of the U-shaped members, the U-shaped members fit somewhat loosely within the notch and permit a limited amount of independent floating movement for each 4of the U-shaped members v46 and 48, whereby the'sides thereof will become self-aligned with the opposite sides of the stationary. contact portions I8 when engaging the same, said engagement being clearly 'shown in Fig. 6. The floating movement ofthe inner U-shaped member 48 is limited by engagement of the sides thereof with the adjacent side surfaces of the slide 30. lThe slide 30 is also provided with a transverse slot 66 extending therethrough which accommodates the inturned members 62 of the sides when the sides are moved toward the slide. The floating movement ofthe outer U-shaped member `46 is limited by engagement of the bend thereof with the laterally' extending flat rear portion 56 of the retaining member 54, this engagement being clearly shown in Fig. `6, as well as in Figs. 1 and 3.

a It will be observed from Figs. 1, 3Y and 5 that when the U-shaped members 46 andl 48 are out of engagement withthe stationary contacts, the outer ends of the outer member 46 extend slightly inward toward eachother while the outer ends of the member 48 extend slightly outward away from each other, whereby the respective sides of the members 46 and 48 are not exactly parallel when the switch is open This construction is for the purpose of yassuring positive engagement of the respective sides of the members 46 and 48 members`46 and 48 are each approximately equal to the thickness of the stationary contact portions I 8.

Upon engagement of the sides of the U-shaped members 46 and 48 with the stationary contact portions I8, the end members 62 of inner member 48 cam the sides thereof toward each other into substantially parallel relationship and the end members 62 are received in the slot 66. Similarly, the end members 64 of the outer U-shaped member 46 cam the sides away from each other into substantially parallel relationship upon engagement with the stationary contact portions I8. It will thus be seen that materially greater contacting area is afforded between the U-shaped members of the movable contact and the opposite sides of each of the stationary contact portions I8 as distinguished from the contacting areas afforded in switches of standard construction wherein the movable bridging contact engages only one side of each of the stationary contacts. The increased contacting areas for the movable bridging and stationary contacts offer greater assurance of positive engagement between said contacts and serve to overcome slight manufacturing imperfections and inaccuracies which may exist therein and which otherwise might result in imperfect engagement between the contacting surfaces if the increased contacting areas were not provided.

The foregoing description with regard to the details and functions of the movable bridging contact is equally applicable to the contact at the outer end of the slide shown in Fig. 1 and the slide shown in Figs. 3 and 4. The slide shown in Figs. 3 and 4, however, differs from that shown in Fig, 1 in that a second movable bridging contact of the same construction as contact 44 is mounted in an aperture 68 provided between the slot 34 and the other end of the slide. One end of the aperture 68 is formed with a notch 'I8 corresponding in both depth and width to notch 50, these notches being for the same purpose, namely, to receive the bend portions of a pair of U-shaped members 46 and 48. However, a different type of retaining member is used in connection with the aperture 68 to close the notch I0 than is used to close the notch 50. Said retaining member 'I2 is best shown in Figs. 3 and 4 and comprises a U-shaped member having a connecting or bend portion 14 which serves to close the outer end of notch 10. The sides of the retaining member l2 are substantially parallel to each other and the sides of the slide 38 when mounted thereon. The space between said sides is approximately equal to the thickness of the slide 36. Each of the sides is formed with an aperture 76 to provide a strike-out or ear 18 which ears are respectively bent to be substantially parallel to the connecting portion 'I4 of the retaining member 'l2 whereby the ears I8 and connecting portion 74 comprise a substantially flat portion corresponding in function to the flat rear portion 56 of retaining member 54, in that the former engages the bend of the outer U-shaped member 46 to limit the floating movement of the sides thereof. Each side of the retaining member 'I2 is provided with a pair of oppositely disposed ears 80, each ear being Aapertured, together with the slide 30 to receive suitable securing means such as rivets 82 to maintain thev retaining member and slide in assembled relationship. A second slot 84 corresponding to the slot 66 is also formed in the plate to accommodate the end members 62 of the inner U-shaped member 48 of the second bridging contact.

Each of the U-shaped members 4S and 48 of contacts 44 are provided in opposite edges of their connecting or bend portions with notches 36 and 88, the sides of which notches are adapted to engage the plate 30 adjacent the sides of the notches 50 and 'I0 to prevent appreciable movement of the connecting or bend portions of the U-shaped members in a direction normal to the plane of the slide 3B. Said notches 85 and 88 have a width slightly greater than the thickness of the slide, as shown in Figs. 4 and 5, to permit a small amount of relative movement between each U-shaped member and/or between the U-shaped members and slide to better facilitate the self-aligning of the respective sides of the U-shaped members with the sides of the stationary contacts.

As will be seen in Fig. 4, the width of the sides of the U-shaped members 4S and 48 comprising the second bridging contact is slightly less but approximately the same as the width of the'aperture 68 whereby said contact may be assembled on the slide by passing one side of each of the U-shaped members 46 and 48 through the aperture B8 and then sliding the U-shaped members longitudinally of the slide until the connecting or bend portions thereof are disposed in the notch 10. Following this, the retaining member 'I2 is inserted within the aperture and secured in place by rivets 82.

The elements which comprise' the circuit for the switch shown in Fig. 1 are: terminal 2G; fuse 22; stationary contact I6; movable contact 44; stationary contact I4; and terminal 2B. In Fig. 3, the elements which comprise the circuit in each switch are: terminal 2S; adjoining stationary contact I4; movable contact 44; stationary contact I6; fuse 22 stationary contact I6 on the second insulating block; the other movable contactI 44; the stationary contact I4 on said second insulating block; and terminal 28.

It will thus be seen that the present invention proyides a movable slide having` either one or two engaged thereby is permitted in order to insureproper engagement between the adjacent surfaces of the movable and stationary contacts.

' While the invention has been illustrated and described in its preferred embodiment and has included certain details, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways, falling within the scope of the invention as claimed.

What I claim is:

1. A switching member adapted for movement between opposite spaced stationary switch contacts and comprising in combination, a substantially nat plate of insulating material, a bridging contact carried thereby and comprising a plurality of nested substantially U-shaped members affording a plurality of surfaces adapted to respectively and substantially simultaneously engage one of the opposite sides of both of said stationary contacts to electrically connect the same when moved into contact therewith, the connecting portions for the 'sides of said U-shaped members extending between said sides, respectively, in the direction of the thickness of said flat plate and the two sides of each of said U-shaped members being disposed at the opposite flat sides respectively, of said at plate, each of said U- shaped members being bodily movable in said direction, and interfltting means on each of said connecting portions and on said plate for limiting the bodily movement of said U-shaped members in said direction.

2. A switching member adapted for movement between opposite spaced stationary switch contacts and comprising in combination, a bridging contact comprising a pair of nested substantially U-shaped members, and a substantially flat plate of insulating material provided with a notch to receive the connecting portions for the sides of said U-shaped members and saidnotch having a depth greater than the combined thickness of said connecting portions to permit limited bodily iloating movement of said U-shaped members with respect to said plate in the direction of the plane of the plate, 'said U-shaped members alfording a plurality of surfaces at both of the opposite sides of the plate adapted to respectively and substantially simultaneously engage one of the opposite sides of both of said stationary contacts to electrically connect thesame when moved into contact therewith and the limited floating movement of said U-shaped members permitting selfaligning of said surfaces of the bridging .con-

tacts with said sides of said stationary contacts,

and coengaging means on the connecting portions of the bridging contact and on the plate adapted to limit relative movement between the contact and plate in a direction normal to the plane of the plate.

3. A switching member adapted for movement between opposite spaced stationary switch contacts and comprising in combination, a bridging contact comprising a pair of substantially U- shaped members each having a notch extending inward from one edge of the connecting portion for the sides thereof, and a substantially flat plate of greater width than thickness and formed of vinsulating material having a thickness slightly less than the width of said notches in said members and provided with anotch to receive said connecting portions of said U-shaped members and said notch in said plate having a depth greater than the combined thickness of said connecting portions tov permit limited floating movement of said U-shaped members with respect to said plate,

said U-shaped members affording a plurality of substantially flat spaced members each having a surface overlying the wider surfaces of said plate and adapted to respectively engage one of the opposite sides of both of said stationary contacts to electrically connect the same when moved into contact therewith and the notches in the connecting portions of said U-shaped members re ceiving a portion of said plate to prevent appreciable movement of said connecting portions in a direction normal to the wider surfaces of said plate.

4. A switching member adapted for movement between opposite spaced stationary switch contacts and comprising in combination, a substantially fiat plate of insulating material and a bridging contact comprising a p air of nested substantially Ushaped members loosely connected to said plate and providing a plurality of substantially nat spaced members each having al surface adapted to respectively engage one of the` opposite sides of both of said-stationary contacts to electrically connect the same when moved into contact therewith, the outer ends of the inner U-shaped member being bent toward each other and the outer ends of the outer U-shaped member being bent away from each other to provide guiding surfaces to facilitate engagement of said at spaced members with the opposite sides of said stationary contacts and the portions of the opposite fiat sides of said plate adjacent the bent outer ends of said inner U-shaped member being provided with clearance spaces adapted to respectively accommodate one of said bent ends of said inner U-shaped member when moved toward each other upon engagement with said stationary contacts.

5. A switching member adapted for rectilinear movement between opposite spaced stationary switch contacts and comprising in combination, a substantially flat elongated plate of insulating material having a notch in one end thereof, a bridging contact comprising a plurality of nested U-shaped members each having substantially flat sides respectively spaced apart a distance greater than the thickness of the plate and joined by a connecting portion, the connecting portions of said members being loosely mounted in said notch in said plate to afford limited floating movement of said sides of said members and the connecting portion of the outer U-shapedmember having in one edge a notch slightly wider than the thickness of said insulating plate and adapted to receive one Wall of the notch in the end of said insulating plate to prevent appreciable relative movement between the connecting portion of said outer U-shaped member and plate in a direction normal to said plate, and means secured to said plate and closing the open end of said notch therein to secure said U-shaped members loosely mounted therein, one surface of each of said flat sides being adapted to respectively become selfaligned with and engage one of the opposite sides of both of said stationary contacts to electrically connect the same.

6. A switching member adapted for rectilinear movement between two spaced pairs of opposite spaced stationary switch contacts and comprising in combination, asubstantially ilat elongated plate of insulating material having a notch in one end thereof and a contact receiving aperture intermediate the ends thereof and provided with a notch in one wall thereof, two bridging contacts each comprising a plurality of nested U-shaped members having substantially flat sides and respectively mounted on said plate with the bend portion f said U-shaped members respectively loosely mounted in said notches, said notches each having a greater depth than the collective thickness of said bend portions disposed therein and the loose mounting` of said U-shaped members affording limited oating movement of the said sides with said stationary contacts to electrically connect the pairs of the same, and a plurality of members secured to said plate to respectively close the open end of said notches to secure said contacts respectively therein.

7. A switching member adapted for rectilinear movement between opposite spaced stationary switch contacts and comprising in combination, a,

' substantially flat elongated plate of insulating material, said plate being of greater width than thickness and having a notch in one end thereof, a bridging contact comprising a plurality of nested U-shaped members having sides adapted to respectively engage said stationary contacts, said bridging contact being mounted on said plate with the bend portions of said U-shaped members loosely mounted in said notch to afford limited floating movement of said sides, said sides of said U-shaped members overlying the opposite wider faces of said fiat plate in movable relation thereto, and means secured to said plate and closing the open end of said notch to secure said U-shaped members loosely mounted therein, said means having a portion adapted to engage the bend por- Ition of the outermost U-shaped member to limit the -floating movement thereof.

8. A switching member adapted for rectilinear movement between two spaced pairs of opposite spaced stationary switch contacts and comprising in combination, a substantially nat elongated plate of insulating material having a notch in one end thereof and a contact receiving aperture intermediate the ends thereof and provided with a notch in one wall thereof, two bridging contacts each comprising a plurality of nested U-shaped members having substantially fiat sides and respectively mounted on said plate with the bend portion of said U-shaped members respectively loosely mounted in said notches, the loose mounting of said U-shaped members affording limited floating movement of the side members thereof to permit self-alignment of said sides with said stationary contacts to electrically connect the pairs of the same, and a plurality of members secured to said plate to respectively close the open end of said notches to secure said tcontacts respectively therein', said members being respectively provided with means adapted to engage the outer U-shaped member of each contact to'limit the floating movement thereof.

9. In an electric switch comprising an insulating supporting member and a pair of spaced sta- ,tionary contacts mounted on said member, a substantially planar member of greater Width th'an thickness disposed between and movable with respect to said stationary contacts, a bridging contact carried by said planar member and comprising a plurality of substantially U-shaped members affording a plurality of surfaces overlying each of the two wider-faces of said planar member and adapted to respectively and substantially simultaneously engage one of the opposite sides 0f both of said stationary contacts to electrically connect the same when said bridging contact is moved into engagement therewith, said planar member being provided with clearance adjacent said bridging contact to afford a limited amount of floating movement of the free ends f said U-shaped members in a direction normal to said wider faces of planar member, and interfltting means on the U-shaped members and planar member limiting the movement of the .portions of said U-shaped members connecting the free ends thereof in a direction normal to said planar member.

l0. An electric switch comprising in combinar tion, an insulating supporting member, a pair of spaced stationary contacts mounted on said member, a substantially planar member of greater width than thickness disposed between and movable with respect to said stationary contacts, a bridging contact comprising a pair of nested substantially U-shaped members connected to said planar member for movement therewith and affording a plurality of surfaces disposed at each of the two wider faces of said planar member and adapted to respectively and substantially simultaneously engage one of the opposite sides`of both of said stationary contacts to electrically connect the same when said bridging contact is moved into engagement therewith, said planar member being provided with clearance adjacent said bridging contact to alford a limited amount of oating movement of the free ends of said U-shaped members in a direction normal to said Wider faces of said planar` member, and interfitting means on the outermost of the U-shaped .members and planar member limiting the movement of the portion of said outermost U-shaped member connecting the free ends thereof in a direction normal to said planar member.

l1. An electric switch comprising in combination, a pair of spaced contacts stationarily mounted in Velectrically insulated relationship, a substantially planar insulating member disposed between and movable with respect to said stationary contacts, and a bridging contact connected to said planar insulating member. and comprising a pair of nested substantially U-shaped members respectively provided with a notch extending inf ward from one edge of the portion connecting the free ends of `said members and said U-shaped members affording a plurality of surfaces adapted to respectively and substantially simultaneously engage one of the opposite sides of both of said pair of stationary contacts to electrically connect the same when said bridging contact is moved into engagement therewith, said planar insulating member being of greater width than thickness and being provided with clearance adjacent said bridging contact to alford a limited amount of floating movement of the free ends of said U- shaped members in a direction normal to the wider plane of said planar insulating member and the walls of the notches in the connecting portions of said U-shaped members being adapted to respectively engage opposite sides of said planar insulating member to limit the movement of said connecting portions in a direction normal to said planar insulating member.

vPAUL M. CHRISTENSEN. 

